Yes, actually, it is, in the context of there being two, spuriously postulated dichotomous outcomes, whereas it is clearly the case that neither is true. What would it mean for a personality to be fixed? Such a thing doesn't even begin to make any sense, given that persons develop over their lifetimes, for instance. What would it mean that you could change who you are? That also doesn't make much sense, since it is like pulling yourself up by your own bootstraps.

The personality is a constellation of aspects that we all show to varying degrees, many of which are in fact out of our control, but some of which nevertheless are capable of being adjusted in accordance with various forms of conditioning. It is in that constellation that we find what the personality is. Emphasizing minute aspects and exaggerating them doesn't constitute the whole personality. This is remarkably uninformative as an article.